Risk Factors For Breast Cancer-related Upper Extremity Lymphedema:A Meta-analysis

Objective : In recent years, many studies have examined the risk factors for lymphedema after breast cancer treatment, but the conclusions are not consistent, and even some are conflicting each other. This study systematically evaluates the risk factors for upper extremity lymphedema after breast cancer treatment and the strength of their associations with the system evaluation methods to provide a scientific basis for the clinical work-related upper extremity lymphedema in breast cancer early prevention.Methods: Pub Med, Ovid, EMbase, and the Cochrane Library were searched to identify clinical trials published up to December 2012, and their references were retrieved in order to obtain additional information. Search terms include "Breast neoplasms", "Upper extremity lymphedema", "Risk factors" and so on. The quality of included studies was assessed by the Newcastle Ottawa Scale. To establish a database and initial operationdataby excel 2007, and analysis was performed by Stata 10.0 and Rev Man 5.2, the strength of associations between risk factors and breast cancer-related upper extremity lymphedema was described as odds ratio(OR)and 95% confidence intervals(CI). Their heterogeneities between studies were evaluated by the I-squared tset. When there were statistically homogeneity among the study results(P> 0.1, I2 ≤50%), data was analyzed using a fixed effects model;while significant heterogeneity(P <0.1, I2> 50%), then data was analyzed using a random effects model. Publication bias using Egger’s linear regression analysis, P<0.05 was considered statistically significant.Results: Twenty-two studies involving 10106 patients were included in the meta-analysis. The quality of included studies were evaluated by the Newcastle Ottawa scale(Newcastle Ottawa Scale, NOS) evaluation criteria. There were 22 documents, which 13 were rated as Class A, 9 as Class B, so they were high quality studies. By combining analysis of risk factors usin the random effects mode, the results showed the risk factors for upper extremity lymphedema after breast cancer treatment mainly included axillary lymph node dissection(OR=2.72, 95%CI=1.06-0.99, P=0. 038), hypertension(OR=1.84, 95%CI=1.38-2.44, P=0.000), body mass index(OR=1.68, 95%CI=1.22-2.32, P=0.001), and radiotherapy(OR=1.65, 95%CI=1.20-2.25, P=0.002), while no significant associations were found for such factors as chemotherapy, age, number of positive lymph nodes, and number of dissected lymph nodes by using Stata 10.0 and Rev Man 5.2 for data analysis.Conclusions: The incidence of upper extremity lymphedema is higher among patients with breast cancer after treatment. However, different studies have reported vary incidence greatly. This article included in the literature reported the incidence varied from 0.6% to 60.4%. Axillary lymph node dissection, hypertension, body mass index, and radiotherapy are the main risk factors for lymphedema after breast cancer treatment by evaluation and analysis system.